For example, as described in PTL 1 (JP-A-2004-39818), in a rotating head (rotary head) type component mounting device, multiple nozzle holders are provided on a rotating head in a lowerable manner at predetermined intervals in a circumferential direction of the rotating head, each suction nozzle is held on each nozzle holder pointing downward, the rotating head is rotated around an R axis (vertical axis) by an R-axis driving mechanism, the multiple nozzle holders are revolved in the circumferential direction of the rotating head together with the suction nozzles held by the multiple nozzle holders, and pickup of a component is performed by lowering one nozzle holder by a Z-axis driving mechanism at a predetermined position on the revolving path, then, after raising the suction nozzle that performed component pickup operation to a component transport height, each nozzle holder is rotated around a central axis line (Q axis) by a Q-axis driving mechanism, such that a direction (angle) of each component held by each suction nozzle held by each nozzle holder is corrected. Note that, the Q axis is also referred to as the θ axis.
With a component mounter with this type of rotary head, as disclosed in patent literature 2 (JP-A-2013-191771), an imaging device for imaging a component held by a suction nozzle from the side is arranged near the rotary head, and a cylindrical background member that acts as the background to the side image of the component imaged by the imaging device is provided protruding downwards from a central portion of a lower surface of the rotary head.